commit 80f78b773f92048944a850efb7b60629643370cd
author Praveen Chavan <pchavan@codeaurora.org> Wed Apr 06 01:10:59 2016 -0700
committer Wei Jia <wjia@google.com> Tue Jul 12 10:07:37 2016 -0700
tree c7c335515bec654f6baffbb57b997a018937d58f
parent bf6dc1af5bd88135f47c2489c03cdb9f95d57927

MPEG4Writer: Handle writing multiple NAL units in a video sample

Encoder may prepend extension NALs (eg: AVC SVC extension NAL
for temporal layer info) to the VCL NAL.
Look out for non-VCL NALUs preceeding the slice NALs and write
them out separately.
Search for a limited size since such NALs are of small size.

Bug: 27596987
Change-Id: I434c5252098faca99c0ee18e6bc5f43a67718eba
(cherry picked from commit 7941196cf2f21c1a59c5cb2e8b93bbb6f7ff463c)

include/media/stagefright/MPEG4Writer.h

diff --git a/include/media/stagefright/MPEG4Writer.h b/include/media/stagefright/MPEG4Writer.h
index a6901a8..fc97665 100644
--- a/include/media/stagefright/MPEG4Writer.h
+++ b/include/media/stagefright/MPEG4Writer.h
@@ -187,6 +187,7 @@
     // Acquire lock before calling these methods
     off64_t addSample_l(MediaBuffer *buffer);
     off64_t addLengthPrefixedSample_l(MediaBuffer *buffer);
+    off64_t addMultipleLengthPrefixedSamples_l(MediaBuffer *buffer);
 
     bool exceedsFileSizeLimit();
     bool use32BitFileOffset() const;

media/libstagefright/MPEG4Writer.cpp

diff --git a/media/libstagefright/MPEG4Writer.cpp b/media/libstagefright/MPEG4Writer.cpp
index 24fb987..0209f59 100644
--- a/media/libstagefright/MPEG4Writer.cpp
+++ b/media/libstagefright/MPEG4Writer.cpp
@@ -43,6 +43,7 @@
 
 #include "include/ESDS.h"
 #include "include/HevcUtils.h"
+#include "include/avc_utils.h"
 
 #ifndef __predict_false
 #define __predict_false(exp) __builtin_expect((exp) != 0, 0)
@@ -1162,6 +1163,37 @@
     }
 }
 
+off64_t MPEG4Writer::addMultipleLengthPrefixedSamples_l(MediaBuffer *buffer) {
+    off64_t old_offset = mOffset;
+
+    const size_t kExtensionNALSearchRange = 64; // bytes to look for non-VCL NALUs
+
+    const uint8_t *dataStart = (const uint8_t *)buffer->data() + buffer->range_offset();
+    const uint8_t *currentNalStart = dataStart;
+    const uint8_t *nextNalStart;
+    const uint8_t *data = dataStart;
+    size_t nextNalSize;
+    size_t searchSize = buffer->range_length() > kExtensionNALSearchRange ?
+                   kExtensionNALSearchRange : buffer->range_length();
+
+    while (getNextNALUnit(&data, &searchSize, &nextNalStart,
+            &nextNalSize, true) == OK) {
+        size_t currentNalSize = nextNalStart - currentNalStart - 3 /* strip start-code */;
+        MediaBuffer *nalBuf = new MediaBuffer((void *)currentNalStart, currentNalSize);
+        addLengthPrefixedSample_l(nalBuf);
+        nalBuf->release();
+
+        currentNalStart = nextNalStart;
+    }
+
+    size_t currentNalOffset = currentNalStart - dataStart;
+    buffer->set_range(buffer->range_offset() + currentNalOffset,
+            buffer->range_length() - currentNalOffset);
+    addLengthPrefixedSample_l(buffer);
+
+    return old_offset;
+}
+
 off64_t MPEG4Writer::addLengthPrefixedSample_l(MediaBuffer *buffer) {
     off64_t old_offset = mOffset;
 
@@ -1684,7 +1716,7 @@
         List<MediaBuffer *>::iterator it = chunk->mSamples.begin();
 
         off64_t offset = (chunk->mTrack->isAvc() || chunk->mTrack->isHevc())
-                                ? addLengthPrefixedSample_l(*it)
+                                ? addMultipleLengthPrefixedSamples_l(*it)
                                 : addSample_l(*it);
 
         if (isFirstSample) {
@@ -2593,7 +2625,7 @@
             trackProgressStatus(timestampUs);
         }
         if (!hasMultipleTracks) {
-            off64_t offset = (mIsAvc || mIsHevc) ? mOwner->addLengthPrefixedSample_l(copy)
+            off64_t offset = (mIsAvc || mIsHevc) ? mOwner->addMultipleLengthPrefixedSamples_l(copy)
                                  : mOwner->addSample_l(copy);
 
             uint32_t count = (mOwner->use32BitFileOffset()